Abstract: On January 7, 2025, an M_\mathrmW 7.1 earthquake struck Dingri, Xizang, causing severe engineering damage in the epicentral area. To scientifically reconstruct the ground motion impact field of this event, a strong ground motion simulation model was established based on the stochastic finite-fault method, incorporating the inverted source rupture process. A systematic study on key sensitive parameters was conducted: by comparing the mean values of 30 stochastic realizations with the pseudo-acceleration spectra (PSA) recorded at early warning stations, the optimal stress drop was determined to be 10.0 MPa; meanwhile, the high-frequency attenuation parameter (\kappa ) was estimated as 0.0326 based on the negative correlation between its median value and site V_\mathrmS30 . After calibrating the source, path, and site parameters, a reliability test was performed using observational data from the National Seismic Intensity Management and Early Warning Project. Consequently, the gridded distributions of peak ground acceleration (PGA) and instrumental seismic intensity were generated, and the spatial distribution characteristics and formation mechanisms of the strong ground motion field were quantitatively discussed. The results indicate that: (1) Under a 5% damping ratio, the simulated PSA values match the observations well in both amplitude and spectral shape within the period range of 0.04–4.00 s. The residuals mainly fall within the range of \pm 1.0 without significant period dependence, verifying the reliability of the model in the complex crustal environment of the southern Qinghai-Xizang Plateau. (2) The simulated ground motion intensity isovalues exhibit a nearly north-south elliptical distribution. The peak PGA near the epicenter reaches 1184.3 Gal, with a calculated instrumental seismic intensity of 9.6. While covering the actual seismic damage risk, the simulation results show good consistency with both macro-seismic investigations and instrumental observations. (3) The ground motion intensity field clearly demonstrates significant rupture directivity and hanging-wall effects. Specifically, the PGA in the forward rupture direction (northward) is approximately 1.82 times that in the backward direction, and the PGA on the hanging wall is amplified by approximately 1.85 times compared to the footwall. These refined spatial distribution characteristics provide a dynamic basis for explaining macro-seismic damage variations and offer important scientific references for the seismic design of rural buildings and emergency response in southern Xizang.